Overwind prevention device for a self-winding watch



g- 9, 1965 M. KONRAD Q 3,2643% OVERWIND PREVENTION DEVICE FOR A SELF-WINDING WATCH Filed April 15, 1963 e Sheets-Sheet 1 9, 1966 M. KONRAD 326ml OVERWIND PREVENTION DEVICE FOR A SELF-WINDING WATCH Filed April I5, 1963 6 Sheets-Sheet 2 Aug. 9 1966 M. KONRAD 3,2643% OVERWIND PREVENTION DEVICE FOR A SELF-WINDING WATCH Filed April 15, 1965 s Shets-Sheet :5

Aug. 9, 1966 M. KONRAD 3,264,819

OVERWIND PREVENTION DEVICE FOR A SELF-WINDING WATCH Filed April 15, 1963; e Sheets-Sheet 4 Aug. 9, 1966 M. KQNRAD 3,264,319

OVERWIND PREVENTION DEVICE FOR A SELF-WINDING WATCH Filed April 15, 1963 6 Sheets-Sheet 5 9, 1966 M. KONRAD 3,264,819

OVERWIND PREVENTION DEVICE FOR A SELFWINDING WATCH Filed April 15, 1963 6 Sheets-Sheet 6 United States Patent 2 Claims. (Cl. 58-83) Self-winding watches operated by a rocking weight provide for a continuous transmission of the force imparted to the rotary weight to the actual winding mechanism, as long as the watch is worn even after the mainspring has reached its maximum degree of wind.

In order to avoid any excess tensioning leading to a breaking of said spring, slipping springs provided with a sliding keeper are resorted to, but such springs have the drawback of allowing operation beyond the limit of elasticity of the metal, which is detrimental to the efiiciency of the spring and finally leads to its breaking. For this reason, it has already been proposed to replace such springs by a spring associated with a device fitted between its two ends in a manner such that said device uncouples the rocking weight or rotor from the ratchet wheel on the barrel of the Winding mechanism when the spring reaches a predetermined tension.

The object of this invention is to provide a device of this type having a reduced volume and which does not extend beyond the barrel ratchet.

I have illustrated, in the accompanying drawings, by way of example, five embodiments of my invention. In said drawings:

FIGS. 1 and 2 are a plan view and a sectional view through line II-II of FIG. 1 of a first embodiment, respectively.

FIGS. 3 and 4 are two different views of a detail of the latter for two different operative positions.

FIGS. 5, 6 and 7 are plan views of a second, third and fourth embodiment respectively.

FIGS. 8 and 9 illustrate different operative positions of a fifth embodiment shown in plan view.

The embodiment illustrated in FIGS. 1 to 4 includes a barrel 1 connected, through the usual gear work which is not illustrated with the balance wheel 2. Reference character 3 designates the oscillating winding mass rocking round a central spindle 3a carried by the bridge of the selfwinding mechanism 3b and it is provided furthermore with a pinion 30 which, through conventional gears 4, actuates the wheel (FIG. 1).

Reference character 6 designates the barrel drum secured to the spindle 7 revolvably fitted between the plate 8 and the barrel bridge 9, or barrel bar. Reference character 10 designates a core fitted over the spindle 7 while the main spring 11 secured through its inner end to said core has its outer end secured to. the barrel drum, which meshes with the center pinion 6a. Reference character 6b is the center seconds gear. The core 10 carries the ratchet wheel 12 on which is mounted the eccentric spindle 13. The wheel 5 already referred to revolves freely round the barrel spindle 7 and is prevented from vertical shifting thereon by a key 14.

In the lower surface of the wheel 5 is provided a circular groove inside which is housed the coupling member 15 which is cut from a plate of elastic material and assumes the general shape of a U of which the two arms are adapted to mate outwardly with the inner surface of the wheel 5 when in their expanded condition. Between said two arms is housed the wheel 17 adapted to revolve freely round the eccentric spindle 13 and provided with teeth along a portion of its periphery and also with two diametrically opposed notches 17b and 170. Said teeth cooperate with a projection 16 rigid with the spindle 7, while 3,264,819 Patented August 9, 1966 the arms of the coupling member 15 are provided inwardly with two diametrically opposite projections 13 with reference to the wheel 17.

The watch operates as follows:

In FIG. 3, the main spring is assumed to be in its completely expanded condition, in which case the notches 17b and are at a distance from the projections 18. The rocking weight 3 provides for the winding of said spring by making the ratchet wheel 12 rotate in the direction of the arrow 1. It is assumed that this winding is performed at a speed sufiicient for the spindle 7 to remain stationary during said time. Since the arms of the U-shaped member 15 are expanded by the wheel 17 in contact with its projections, they frictionally engage the edge of the Wheel 5 and the latter rotates with the ratchet wheel 12, in the direction of the arrow 1, round the spindle 7. At each rotation, the wheel 17 engages the projection 16 and makes it turn by one tooth interval, also in the direction of the arrow 1. When wheel 17 has turned an interval of four teeth, for instance, the notches 17b and 170 register with the projection 18 and the arms of the coupling member 15 no longer engage the inner edge of the wheel 5, so that the ratchet wheel 12 is disconnected from the wheel 5, the spring being then completely wound.

The different parts occupy then the positions illustrated in FIG. 4. If the spring then expands, it causes the barrel and the spindle 7 to rotate also in the direction of the arrow 1 causing rotation in the opposite direction of the wheel 17 by one tooth interval. The notches 17b and 170 move away from the projections 18 and produce again a coupling of the ratchet wheel 12 with the wheel 5.

In the embodiments illustrated in FIGS. 5 and 6, the coupling member the shape of which is again that of a U, is secured through its lower arm 15a to the ratchet wheel 12 through the tenons 150, while its upper arm 15b cooperates alone with the wheel 17 which in this example is of the cam type, and the wheel 5. In the embodiment illustrated in FIG. 5, said arm 15b is subdivided into two elastic arms 15c and 15f .of which one cooperates with the wheel 17 and the other with the wheel 5.

In the embodiment illustrated in FIG. 7, 5 designates the toothed wheel controlled by the rocking weight and 12 the spring winding ratchet wheel to which is secured the eccentric spindle 13. Reference character 7 designates the spindle of the barrel drum and 20 the coupling member. Its lower end is secured by the tenons 20a to the ratchet wheel 12, while its upper end terminates with two elastic arms 20b and 200, of which the former is connected with the wheel 5 by the projections 20d, whereas the second arm engages the lever 21 revolvably carried at 21a by the ratchet wheel 12. A wheel 22 is adapted to turn freely round the spindle 13 and is provided with two peripheral arcuate bearing surfaces 22a and 22b and with a series of teeth 22c adapted to engage a projection 23 secured to the barrel spindle 7. The bearing surface 22a has a radius larger than the surface 22b. The rotary lever 21 is provided at its free end with a shoe 21b facing the wheel 22.

During the winding operation, said shoe 21b engages elastically the bearing surface 22a and ensures a rigid connection between the wheel 5 and the ratchet wheel 12. When the winding is at an end, the wheel 22 has been shifted by the projection 23 in a manner such that its bearing surface 22b registers with the shoe 21b which cuts off the connection between the wheel 22 and the ratchet Wheel 12.

In the embodiment illustrated in FIGS. 8 and 9, the coupling means are constituted by a lever 25 pivotally carried in its medial section 25a by the ratchet wheel 12. The toothed wheel 24 provided with a radial bearing surface 24a is adapted to revolve round the spindle 13 cara ried by the ratchet wheel. Reference character 7 designates the barrel spindle carrying the projection 16 cooperating with the teeth on the wheel 24. One of the ends 27 of the lever 25 engages the cam Wheel 24, whereas its other hook-shaped end 28 engages the spring-winding wheel provided with a recess 29 defining in the inner periphery of the Wheel a nose 29a. Reference character 26 designates a spring acting on the lever 25.

FIG. 8 shows the arrangement in its engaged position. At this moment, the bearing surface 24a exerts a pressure on the end of the lever 25 and causes it to turn clockwise round its pivot 25a, which releases the hook 28 from the nose 29a. The winding wheel 5 and the ratchet wheel 12 are then uncoupled and the parts occupy the position illustrated in FIG. 9 for which the hook 28 can only slide over the inner periphery of the wheel 5 without exerting any pressure on the latter. The spring 26 acts, as a matter of fact, through the end 27 of the lever 25 on the bearing surface 24a.

What I claim is:

1. In a watch comprising a barrel drum, a barrel spindle coaxial with the drum, a main spring interconnecting the spindle with the drum and a rocking winding weight, a device for coupling and uncoupling said weight and said spring comprising an outer wheel actuated by the rocking weight, revolvably carried by the barrel spindle and provided with a coaxial circular recess, a ratchet wheel coaxially rigid with the barrel spindle and the rotation of which winds the main spring, a spindle eccentrically carried by the ratchet wheel and facing the recess in the outer wheel, an inner wheel revolvably carried by said eccentric spindle, housed inside the recess in the outer wheel and provided with a series of teeth on at least a portion of its outer periphery, a radial projection rigid with the said barrel spindle and adapted to mesh with last-mentioned teeth to be driven thereby to wind the spring in a direction starting from an unwound towards a fully wound position, an elastic U-shaped mem ber fitted inside the recess in the outer wheel and including two arms the outer periphery of at least one of which is adapted to engage frictionally when expanded the outer surface of the recess in the outer wheel and the inner peripheries of said arms engaging the inner wheel to be urged apart thereby and to urge said arms into engagement with said outer surface of the recess, and cooperating means on the inner wheel and inner peripheries of the arms of the U-shaped member adapted to ensure a receding movement of said arms when the inner 1 wheel has reached an angular position corresponding to the end of the allowed spring winding operation, the inner wheel being thereafter returned to its former position by the unwinding of the spring.

2. In a watch comprising a barrel drum, a barrel spindle coaxial with the drum, a main spring interconnecting the spindle with the drum and a rocking winding weight, a device for coupling and uncoupling said weight and said spring, comprising an outer wheel controlled by the rocking weight, revolvably carried by the barrel spindle and provided with a coaxial circular recess, a ratchet wheel coaxially rigid with the barrel spindle and the rotation of which winds the main spring, a spindle eccentrically carried by the ratchet wheel and facing the recess in the outer wheel, an inner wheel revolvably carried by said eccentric spindle, housed inside the recess in the outer wheel and provided with a series of teeth on at least a portion of its outer periphery, a radial projection rigid with the main spindle and adapted to mesh with last-mentioned teeth to be driven thereby to wind the spring in a direction starting from an unwound towards a fully wound position, an elastic U-shaped member fitted inside the recess in the outer wheel and including two arms the outer peripheries of both of which are adapted to engage frictionally when expanded the outer surface of the recess in the outer wheel and the inner peripheries of said arms engage the inner wheel to be urged apart thereby and to urge said arms into engagement with said outer surface of the recess, and cooperating means on the inner wheel and inner peripheries of the arms of the U-shaped member adapted to ensure a receding movement of said arms when the inner wheel has reachced an angular position corresponding to the end of the allowed spring winding operation, the inner wheel being thereafter returned to its former position by the unwinding of the spring.

References Cited by the Examiner UNITED STATES PATENTS 335,471 2/1886 Moriet 58-83 FOREIGN PATENTS 5,378 1903 Great Britain.

RICHARD B. WILKINSON, Primary Examiner.

LEO SMILOW, Examiner.

G. F. BAKER, Assistant Examiner. 

1. IN A WATCH COMPRISING A BARREL DRUM, A BARREL SPINDLE COAXIAL WITH THE DRUM, A MAIN SPRING INTERCONNECTING THE SPINDLE WITH THE DRUM AND A ROCKING WINDING WEIGHT, A DEVICE FOR COUPLING AND UNCOUPLING SAID WEIGHT AND SAID SPRING COMPRISING AN OUTER WHEEL ACTUATED BY THE ROCKING WEIGHT, REVOLVABLY CARRIED BY THE BARREL SPINDLE AND PROVIDED WITH A COAXIAL CIRCULAR RECESS, A RATCHET WHEEL COAXIALLY RIGID WITH THE BARREL SPINDLE AND THE ROTATION OF WHICH WINDS THE MAIN SPRING, A SPINDLE ECCENTRICALLY CARRIED BY THE RATCHET WHEEL AND FACING THE RECESS IN THE OUTER WHEEL, AN INNER WHEEL REVOLVABLY CARRIED BY SAID ECCENTRIC SPINDLE, HOUSED INSIDE THE RECESS IN THE OUTER WHEEL AND PROVIDED WITH A SERIES OF TEETH ON AT LEAST A PORTION OF ITS OUTER PERIPHERY, A RADIAL PROJECTION RIGID WITH THE SAID BARREL SPINDLE AND ADAPTED TO MESH WITH LAST-MENTIONED TEETH TO BE DRIVEN THEREBY TO WIND THE SPRING IN A DIRECTION STARTING FROM AN UNWOUND TOWARDS A FULLY WOUND POSITION, AN ELASTIC U-SHAPED MEMBER FITTED INSIDE THE RECESS IN THE OUTER WHEEL AND INCLUDING TWO ARMS THE OUTER PERIPHERY OF AT LEAST ONE OF WHICH IS ADAPTED TO ENGAGE FRICTIONALLY WHEN EXPANDED THE OUTER SURFACE OF THE RECESS IN THE OUTER WHEEL AND THE INNER PERIPHERIES OF SAID ARMS ENGAGING THE INNER WHEEL TO BE URGED APART THEREBY AND TO URGE SAID ARMS INTO ENGAGEMENT WITH SAID OUTER SURFACE OF THE RECESS, AND COOPERATING MEANS ON THE INNER WHEEL AND INNER PERIPHERIES OF THE ARMS OF THE U-SHAPED MEMBER ADAPTED TO ENSURE A RECEDING MOVEMENT OF SAID ARMS WHEN THE INNER WHEEL HAS REACHED AN ANGULAR POSITION CORRESPONDING TO THE END OF THE ALLOWED SPRING WINDING OPERATION, THE INNER WHEEL BEING THEREAFTER RETURNED TO ITS FORMER POSITION BY THE UNWINDING OF THE SPRING. 